The present invention relates generally to the production of terminals or connectors and, more particularly, to a method of and apparatus for applying solder beads to such connectors for subsequent attachment to the terminals of an electrical heating grid circuitry formed on a vehicle glazing closure.
A well known expedient for defogging or deicing windows, particularly the rear windows, of automative vehicles and the like is the use of heating circuits comprised of electrical resistance elements. Often these resistance elements are formed of an electrically conducting material formed in a pattern of parallel lines extending lengthwise of the window or in a generally horizontal direction when installed in the vehicle, and which are connected at their opposite ends to electrodes or bus bars located adjacent the opposite ends of the glass sheets and which extend generally transversely thereof. The bus bars, in turn, are adapted to be provided with suitable terminals for connection to the vehicle electrical system. The electrically conducting material of which the parallel lines, bus bars and terminals are formed is imprinted on the inboard or inner surface of the glass sheet in the desired pattern and then fired or fused thereon under high temperature conditions.
While such terminals admirably serve the purpose for which they were designed in fixed glazing closures, problems are encountered when such fused terminals are employed on movable glazing closures, such as the rear windows of station wagons for example because of the problems encountered when opening and closing the movable closure. Rather than employing flexible connectors or conductors leading to such terminals, recent designs incorporate the conductors in the vehicle body that terminate in contacts which are engageable by the terminals of the movable closure when closed to provide a closed circuit for the resistance elements. However, the impact or frictional engagement of the heating circuit's terminals with the vehicle's electrical system contacts causes the fused material to wear and thereby short out and arc, burning off portions of the terminals to disable the heating circuit. In order to eliminate this problem, it has been found desirable to attach, as by soldering, metallic striker plates onto the fused terminals to better accommodate frictional movement of the vehicle's electrical contacts therewith, and thereby protect and prolong the useful life of the terminals.
Preferably, the striker plates are provided with beads of solder formed integral thereon prior to the attachment thereof to the terminals during production. Attempts to apply the solder beads to the plates with ordinary hand operated tools are not only too slow to be economically feasible, but also lack the capability of dispensing uniform amounts of solder onto the plates from plate to plate.